Wet grinding operations, defined by grinding processes using water-based coolant systems, have been found to be hampered with shorter life of the abrasive product as compared with dry grinding applications. This phenomenon typically has been addressed by addition of sealant in the formulation of make resin employed in the abrasive. Chemicals added to the make resin to counteract the effect of water generally include hydrophobic molecules that increase hydrophibicity of the make resin to thereby reduce the intake of water, to retard swelling of the resin system consequent to deterioration of mechanical properties, and to retard abrasive loss. Examples of hydrophobic molecules typically are siloxanes and organo-functional silanes (hereinafter referred to as “silanes”) or other organic molecules that have hydrophobic moieties, such as vinyl bonds, and sulfur or fluorine atoms in the organic molecule. However, inclusion of hydrophobic components in the make resin often does not protect abrasive particles upon contact with water, thereby permitting water over extended use periods to migrate along abrasive particles until the abrasive tool fails. In the case of coated abrasive products, contact of the backing material with water employed as a coolant can cause separation of the abrasive and make coat from the backing material.
In one alternative, abrasive particles are first treated by applying a coating of a silane. Hydrolysis of the silane at a surface of an abrasive particle can cause formation of covalent bonds, particularly where the abrasive particle is a metal. However, formation of a hydrophilic coating on grains can reduce the strength with which particles are held in place by the make coat, particularly where the make coat includes a hydrophobic component, such as a hydrophobic silane component.
Therefore, a need exists for abrasive particles, coated abrasive products and other grinding tools, such as bonded abrasive tools, that overcome or minimize the above-referenced problems.